Laser processing apparatus

Abstract

A laser processing apparatus including a laser light source, a polarizing beam splitter, a first reflective mirror, a second reflective mirror, and a polarizing beam combiner is disclosed. The laser light source is configured to generate a laser light. The polarizing beam splitter is configured to divide the laser light into a first beam and a second beam. The first reflective mirror is configured to reflect the first beam. The second reflective mirror is configured to reflect the second beam. The polarizing beam combiner is disposed on a path of the first beam reflected by the first reflective mirror and on a path of the second beam reflected by the second reflective mirror. An optical axis of the polarizing beam combiner is not parallel to the first beam. The polarizing beam combiner is configured to guide the first beam and the second beam.

What is claimed is: 
     
         1 . A laser processing apparatus comprising:
 a laser light source configured to generate a laser light;   a polarizing beam splitter configured to divide the laser light into a first beam and a second beam having different polarization states, wherein the first beam passes through the polarizing beam splitter, and the second beam is reflected by the polarizing beam splitter;   a first reflective mirror configured to reflect the first beam;   a second reflective mirror configured to reflect the second beam;   a polarizing beam combiner disposed on a path of the first beam reflected by the first reflective mirror and on a path of the second beam reflected by the second reflective mirror, wherein an optical axis of the polarizing beam combiner is not parallel to the first beam, the polarizing beam combiner is configured to receive the first beam and the second beam, and guide the first beam and the second beam; and   a focusing element disposed on a path of the first beam and the second beam guided by the polarizing beam combiner, and configured to converge the first beam and the second beam and form a first speckle and a second speckle separated from each other respectively.   
     
     
         2 . The laser processing apparatus according to  claim 1 , wherein the optical axis of the polarizing beam combiner is deflected relative to the first beam with a rotation axis, wherein the rotation axis is perpendicular to the first beam and the second beam. 
     
     
         3 . The laser processing apparatus according to  claim 1 , wherein the optical axis of the polarizing beam combiner is deflected relative to the first beam with the second beam incident on the polarizing beam combiner as an axis. 
     
     
         4 . The laser processing apparatus according to  claim 1 , wherein the polarizing beam combiner guides the first beam and the second beam to the focusing element in a first direction and a second direction having an included angle. 
     
     
         5 . The laser processing apparatus according to  claim 1 , wherein an incident angle of the second beam to the polarizing beam combiner is greater than 45 degrees or less than 45 degrees. 
     
     
         6 . The laser processing apparatus according to  claim 1 , wherein the first reflective mirror and the second reflective mirror are not parallel to each other. 
     
     
         7 . The laser processing apparatus according to  claim 1  further comprising a first phase retarder disposed on a path of the laser light, and located between the laser light source and the polarizing beam splitter to change a ratio of the first beam and the second beam contained in the laser light. 
     
     
         8 . The laser processing apparatus according to  claim 7  further comprising a second phase retarder disposed on a second optical path between the polarizing beam splitter, the second reflective mirror, and the polarizing beam combiner, and configured to generate a phase difference to the second beam. 
     
     
         9 . The laser processing apparatus according to  claim 7  further comprising a third phase retarder disposed on a first optical path between the polarizing beam splitter, the first reflective mirror, and the polarizing beam combiner, and configured to generate a phase difference to the first beam. 
     
     
         10 . The laser processing apparatus according to  claim 1 , wherein an optical path length of a first optical path between the polarizing beam splitter, the first reflective mirror, and the polarizing beam combiner is the same as an optical path length of a second optical path between the polarizing beam splitter, the second reflective mirror, and the polarizing beam combiner. 
     
     
         11 . The laser processing apparatus according to  claim 1 , wherein the focusing element is a lens or a concave reflective mirror. 
     
     
         12 . The laser processing apparatus according to  claim 1 , wherein the laser processing apparatus is a micro light emitting diode transfer apparatus, and a distance between the first speckle and the second speckle is less than 10 microns. 
     
     
         13 . The laser processing apparatus according to  claim 1  further comprising a carrying platform configured to carry at least one micro light emitting element, wherein the first speckle and the second speckle fall on the at least one micro light emitting element. 
     
     
         14 . The laser processing apparatus according to  claim 13 , wherein a depth of focus of the first speckle and the second speckle formed by the focusing element is greater than a height of the micro light emitting element. 
     
     
         15 . The laser processing apparatus according to  claim 1 , wherein a light-receiving aperture of the focusing element is greater than a product of an included angle between the first beam and the second beam and a light-receiving distance, and the light-receiving distance is a distance from the polarizing beam combiner to the focusing element. 
     
     
         16 . The laser processing apparatus according to  claim 1 , wherein a distance between the first speckle and the second speckle is greater than 2.44λ (f/#), wherein λ is a wavelength of the laser light, and f/# is an aperture value of the focusing element. 
     
     
         17 . A laser processing apparatus comprising:
 a laser light source configured to generate a laser light;   a polarizing beam splitter configured to divide the laser light into a first beam and a second beam having different polarization states, wherein the first beam passes through the polarizing beam splitter, and the second beam is reflected by the polarizing beam splitter;   a first reflective mirror configured to reflect the first beam;   a second reflective mirror configured to reflect the second beam;   a polarizing beam combiner disposed on a path of the first beam reflected by the first reflective mirror and on a path of the second beam reflected by the second reflective mirror, wherein an optical axis of the polarizing beam combiner is parallel to the first beam, the polarizing beam combiner is configured to receive the first beam and the second beam, and guide the first beam and the second beam; and   a focusing element disposed on a path of the first beam and the second beam guided by the polarizing beam combiner, and configured to converge the first beam and the second beam and form a first speckle and a second speckle separated from each other respectively,   wherein the first reflective mirror and the second reflective mirror are not parallel to each other.